With the proliferation of software products and services, attempts have been made to codify and/or standardize the designing of software and software architecture. Examples include:
The Booch Method and Modeling Language (see “Object Oriented Analysis and Design” by Grady Booch);
James Rumbaugh and associates' Object Modeling Technique (OMT);
the Object Oriented Software Engineering (OOSE) method by Ivar Jacobson; and
the Unified Modeling Language (UML) which combines the foregoing and industry best practices.
The UML is a visual modeling language (with formal syntax and semantics) for communicating a model or conceptionalization. Thus the modeling language specification specifies modeling elements, notation and usage guidelines and not order of activities, specification of artifacts, repository interface, storage, run-time behavior and so forth. In general, at the modeling level a “problem” is posed in terms of a customer's needs and requirements and may be referred to as the business problem system. The software designer develops a “solution” software product and or service that addresses the problem. The UML syntax enables software designers to express (specify and document) the subject problems and solutions in a standardized manner, while the UML semantics enable knowledge about the subject system to be captured and leveraged during the problem solving phase. See “UML in a Nutshell” by Simon Si Alhir, published by O'Reilly & Associates, September 1998. As such, the UML enables the sharing of information (including prior solution portions) and extension (without reimplementation) of core object oriented concepts (analysis and design) during the iterative problem-solving process for designing software products.
A property in UML 2.0 can be marked as being a derived union. The collection of values denoted by the property in some context is derived as the strict union (superset) of all the values denoted, in that context, by properties that subset it. A derived property is identified as a union with a union constraint on the supersetting property.
The Rose model for UML 2.0 contains many attributes and associations that are constrained to be derived unions. There are, however, no known mechanisms for generating Java code that enforces these constraints. The Eclipse Modeling Framework (EMF) can be used to generate Java code from a Rose model, but provides no automated support for processing derived unions. Indeed, since all such properties are derived, the EMF discards these properties altogether. Even if these properties were retained, the constraint information is discarded by EMF during code generation.